Arizona, Arkansas and Missouri look like unlikely pickups for Democratic Senate candidates to win in 2016. But Democrats are preparing for the unlikely.

You don't need to look any further back than 2012, when despite a favorable GOP climate, mistakes by two favored Republican candidates kept the party from winning control of the Senate.

Last week, the Democratic Senatorial Campaign Committee recruited former U.S. Attorney Conner Eldridge to take on Republican Sen. John Boozman in Arkansas — a state where Democrats lost the past two Senate races. But Democrats say Eldridge has the kind of background that could appeal to voters in the deep red state in the case of an opening, and say his entrance into the race could expand the map as the party seeks to win the majority next November.

Eldridge joins two other Democratic recruits who could forge paths to victory in the right political environment: Rep. Ann Kirkpatrick in Arizona and Secretary of State Jason Kander in Missouri. Both are adept politicians who face strong GOP incumbents in states that lean Republican in presidential years, but could swing the Democrats' way in the event of unforced Republican errors.

"It doesn’t always work, but if you put the pieces together and put the race on the map, only good things can happen," said Ben Ray, a Democratic operative who helped Sen. Joe Donnelly to victory in Indiana in 2012, when Republican Richard Mourdock's ill-advised comments about rape helped Donnelly win an otherwise dark red state.

Republicans scoffed at the Democrats' strategy.

"The DSCC is clearly grasping at straws and trying to deflect attention from the fact that they have struggled to recruit in Obama states and they have several competitive primaries that are going to make their general election chances a lot harder," said Andrea Bozek, communications director for the National Republican Senatorial Committee.

But Adrianne Marsh, a Democratic strategist who worked on Missouri Sen. Claire McCaskill’s 2006 and 2012 campaigns, said McCaskill benefited from the outrage caused by her opponent Todd Akin's "legitimate rape" comment. In the same year, Donnelly capitalized on similarly insensitive remarks from Mourdock.

An unpalatable GOP presidential nominee could also shift the tide towards Democrats, giving them an opening down the ballot. With businessman Donald Trump — who has broken nearly every convention in running a presidential campaign as he's offended significant segments of the electorate — as the Republican front-runner, there's a chance that could happen.

“If it’s Trump, you’re going to get a lot of people who are very upset about his candidacy. If they go with someone more mundane, the disappointment for others could very well carry into the general election,” Marsh said.

In other cases, Democrats might be able to benefit from slowly "chipping away" at an otherwise popular Republican’s credibility by tying them to Washington and a Congress which has been repeatedly panned by the public — a strategy already embraced by D.C. outsiders such as Kander and Eldridge.

A similar strategy paid off for Republicans in 2014 as they took the Senate majority for the first time since 2006. The GOP seized upon President Barack Obama's unpopularity and an electorate dissatisfied with the status quo.

Last cycle, Senate Republicans needed to net six seats to win a majority, and had a favorable map to get there as Democrats defended incumbents and open seats in deeply red states such as Alaska, Arkansas, Louisiana, Montana, South Dakota and West Virginia.

But, Republicans pushed the map's limits to net nine seats, defeating Democrats in purple or even blue states such as Colorado and Iowa by recruiting Cory Gardner and Joni Ernst — who went on to be some of the GOP's strongest nominees.

Even in New Hampshire and Virginia, Republicans recruited competitive candidates who forced Democrats to spend time, energy and money — even if the GOP nominees did not win.

There's no guarantee the right atmospherics will emerge for Democrats — especially in a state such as Arkansas, where Democrats have almost disappeared in the Obama era.

"Each of those senators are established enough to have that degree of separation and to have enough of a cushion to blunt the impact,” Brian Walsh, who led the NRSC's communications shop from 2009 until 2013, said of GOP incumbents in Arizona, Arkansas and Missouri.

And, Democrats still have work to do in recruiting, as they look for five victories to regain control of the Senate.

But Democrats are confident they will find candidates for those races, and say their job in the off-year is to prepare for any positive events that may occur.

"Winning the majority means finding top-notch candidates to take on vulnerable GOP incumbents in as many states as possible, not just the blue and purple ones," said Justin Barasky, communications director at the Democratic Senatorial Campaign Committee. "And that's exactly what we're doing."

Correction 12:36 p.m. A previous version of this article misspelled Conner Eldridge's name.